If it tells you anything, I made this yogurt for the first time Sunday evening. Monday evening we had our first bowl. It is now Wednesday morning and I have to make more again. We've gone through a half-gallon of yogurt in 3 days.
It's sweet without sweeteners and comes out to about the consistency of my favorite greek yogurts.

Homemade Yogurt
printable recipe
Ingredients:
8 cups whole milk
½ cup plain live active yogurt
Directions:
In a large pot bring the milk to a boil, then remove from heat. Let it cool just until it is cool enough to stick your pinky finger in the milk and hold for 10 seconds. (We did a temp reading and we've found the exact temperature each time is 122°)
Remove 2 cups of the milk and pour into a medium bowl. Whisk together with the active yogurt until smooth and blended. Pour this mixture back into the milk pot and whisk again until combined and smooth.
Pour the milk into an airtight container and place in a warm spot overnight (We set it on the floor near, but not on top of, a heating vent.
The next morning place the container(s) in the refrigerator and chill completely.
Adapted from No Impact Man and Super(Natural)Momma